Filter



FILTER J. L. LUCAS May 17, 1960 Filed Oct. 31, 1956 United States Patent FILTER v James L."Lucas, Charlotte,.N.C., assign'orto George'K,

JLe Brun and Aubrey H. Terrell, both of Bethesda, Md. Y

Application October 31,11956,;Seria1'No.,619,587

2'Claims. (Cl. 183-51)v` ice on the line 2--2 of Fig. 1, lookingin .the direction of the arrows; Y l l .Y

Fig. 3 is. a stillfurther enlarged fragmentary sectional View taken on the line 3-3 of Fig. 1, withthe channel shaped side member and filter medium omitted;

Fig. 4 is a fragmentary sectional view taken on the lines 4-4 of Fig. ,1, looking -in the direction of the arrows, and Y, Y

Fig. 5 is a perspective view showing alslig'htlyy modified form of the means forretaining the filter medium in an operativeposition,v Showing the relaxed position thereof in `full lines and theposition assumedin use inv dotted lines. Y v

Referring now to Fig. v1 of the drawings, whereinfthere is shown a filter unit AIt) comprisingchannel vshaped side members 12, 14 and channel shaped end members 16, 18'.`

mesh orforaminous construction. When such filters become clogged, they are discarded. vDiscarding ytheV prior art filters entails considerable 'economic waste, as the frame andthe supporting surfacefor the filter medium are not usually `damaged or otherwise rendered useless position in the frame'.

Another object of this inventionisftoprovide a filter having `a rectangular frame, channelY shaped in cross sectionfand having resilientV means releasably'holding a filter medium in the'frame. l A

A further object of this inventionisgto provide an endless band type resilient means Vforfretaining .a'lter medium in its'frame.r y

An additional `object of this `invention to 4provide an endless band typefilter retainingl means having combined strengthening and 1finger engaging means incorporatedv therewith.;..y f K Yet another object `ofvthis invention -isv to provide a filter retaining means comprising an endless band ofnspring material having means forfinger engagementtherewitb.

Another object Vofthis invention "isto provide a filter medium retaining means comprising an endlessband a majorporti'on of which is spaced above fthe plane .ofithe filter when inoperative position.

further object of thisu invention is to provideran endlessrband filter medium retaining means -whieh'willnot appreciably abrade the filter medium when being placed in operative position.

The above and other objects will become apparent inA the following specification taken withy the accompanying drawings forming a part thereof. Y

In the drawings wherein like characters of reference refer to like parts in the several figures: v

Fig. l is a plan View of the filter showing the retaining means in operative position in dotted lines and showing in dot-dash lines the manner of inserting and removing said means;

Fig. 2 is an enlarged sectional view taken substantially The side members 12, 14 and the end members 16, 18 are joined at their ends 19in any suitable manner, as by spot welding, soldering orthey may be integral, to form a shallow rectangular box fratrie'.V Each ofthe side and lend members 'is substantiallyk U-shaped in cross section and definesa channel having a relatively .wide bottom web 20 disposed in a plane and illustratedasbeing substantiallyhorizontah a relatively narrow overhanging top web 22 disposed ina plane substantially parallel to the Yplane of the web 20, yand an intermediate side member 24 disposed in a plane substantially normal to .the plane of the webs 20 and V22. The intermediateside member Q24 is secured along 'its longitudinal edges, vas at 25, tothe, outer peripheraledges of themeinbersk 20, 22. `0n the 'bottomwebs V'20","there is secured anp'ope'n mesh or 'foraminous sheet 26 for supporting a "filter medium ,28,to'be hereinafterdescribed. y Y

The channel frame members 12, 114',v 1'6 :18,.are each formed of suitable sheet `metal but 'they may be formed as channels by extrusion of either metal orplastic,

and may-be joined as above described or in any suitable ,well known manner. The filter medium supporting sheet 26 may be formed v,by a plastic molding proeess,gor it may be formed from sheet fmetal bythe expandedmetal y process.- s l Asheet'material filter mediumnZS is cut toa size to fit the configuration of the filter VunitY 10, :andrests yon the supportf26 and'engag'esthe channel side members 24.

While any sheet filterjmaterial may be used, I prefer to useV a 'cellulosic batting or lap type material known `plastic is.` employed to retain the filter mediumI inoperative i position in :the filter unit 10.

At 'diametrically 'opposedr sides on kthe yband r32,1;there `are. secured handle-forming channel members 34, each having 'Va-relatively wide'intermediate top web 36,.a'de- Ypending-outerside 38.1and a ,dependingY ,finger gripping inner-H1340. vThe respective outer side-3, 8.and the :inner lip;4.0. are disposed `,in Eplanes substantially parallel.` to the respective members 24. lThe side 38 is turned back upon itself to provide a longitudinal edge moving a smooth round surface 41 which directlyengages the filter medium 26 at the maximum outer extremity thereofto provide a` maximum lter area. The turned back portion 42 is parallel to and spaced from the outer side 38 a distance substantially equal to the thickness of ythe-band 32 and l the turned portion 42 defines with the outer sides 38 a clamping and stifi'ening element which is U-shaped in cross section and through which the band 32 passes, see Figures 1-3. Y

As heretofore described the band 32 is endless and is carried by each of the channel members 34 through the Patented'My 17, 1960 Y resilient propertiesof the turned portion' 42 and the outer sides 38. If desirable, and as illustrated, indentations such as crimps or pinches 43, note Fig. 3, may be formed in each turned back portion 42 in order to more Vreadily secure the band 32 between thel portion 42 and sides 38. However, such crimpsor pinches are' not absolutely vnecessary andthe band 32 may be easily removablyretained in a desired position between the portions 42 and sides 38' without using such indentations.. It is to be understood that the endless band 32 is continuously exerting an outward pressure which retains the filter medium 28 in its desired position. l

As a modification of the retaining means 30 there is illustrated in Fig. two relatively short resilient spring elements 32', 32" each having an end thereof permanently secured within the U-shaped-clamping and stiffen ing elements defined" by the turnedrportions 42 and the outer sides 38 ofthe respective channel members 34, by means of rivets 48 or other suitable securing means.

Similarly a singleband of spring material may be used wherein only its two ends will be permanently held within the U-shaped portions of one channel mmeber 34 with the intermediate portion ofthe band secured as disclosed above Yto the other channel member 34. This modification is not detailed in the drawings, but is believed to be within the inventive concept as illustrated herein.

Attention is directed to Figure 5 wherein there Yis 'illustrated the disposition of the'portion of the -band 32', 32" which is intermediate the respective channel members 34, and it is to be noted that these portions of the band which are designated generally as loops 50, 52 are spaced, as illustrated at 53, from the curved angle portions 54 of the filter medium 28, so that the loops 50, 52 engage the portion of the filter medium which is in contact with the channel wall 24 to insure that the maximum pressure may be exerted against the filter medium to retain it in the desired position with the maximum area thereof available for filter purposes.

It is also to be understood that the members 36 may be formed of metal or plastic as described above in regard to the membersr12, 14, 16, 18 and 26.

To assemble Vthe filter, the sheet of filter medium 28 is placed loosely in the channel side members 14, 16 and end members 18, and 20, and theretaining means 30 is grasped by the channel membersr34rand drawn into a long narrow oval by bringing one member 34 into proximity to an end loop, 50 or 52, as shown in Fig. 1, to create elongated end looped portions S6 and 58. The .rend loop 58 is then placed against the filter medium 28 and thrust into the channel end member 16as shown in dot-dash lines in Fig. 1. VThe other member 34 is then placed in the channel `side member 12 as shown in fdot-dash lines in Fig.' 1, and the first mentioned member 34 is then moved toward the channel side member 14.y Upon release of said first member 34, the retaining means 30 enters the channel side members 12,-14 and the end member 18, with the elongated loop 56 changing shape into` that. as shown by the dashV lines for the band 32 and the solid lines for the members 34 in Fig. l. The resiliency of the band 32'causes it to press the marginal portions of the lter medium '28 against the sides 24, and to' stretch as detailed above.

the portion thereof over the support 26 into a substantially taut condition.`

To remove the filter medium, for replacement, the procedure above outlined is reversed. The finger engaging lips 40 are grasped and the band 32 is brought to the position shown in dot-dash lines in Fig. 1, whence it is removed and the filter medium is removed to be replaced The band`32 engages snugly into the angle formed by the sides 24 and the webs 20 and retains the filter medium-28 securely against the bottom supi port 26.

It should beapparent that Ihave devised a filter, which can be sold to users of air conditioners and warm air heaters etc., and which is permanent. In order to renew the filtermg ability of the filter, it is necessary only to remove an inexpensive sheet of filtering medium which can be done in a few seconds; and at much less cost end thereof secured to the other of fsaid clamping and than that of replacing conventional filters.

It is to be understood that modifications may be made in the above described invention within the skill of the operator and the scope ofthe appended claims.

I claim:

l. In aiilter unit comprising a rectangular frame having channel-shaped sides and ends vsecured together to deiine a shallow box, having an open top and bottom, a foraminouslter supporting member secured to the bottom of the box, a sheet of filter medium covering the fo-i raminousrmember and having marginal portions disposed in the channel-shaped sides, the improvement comprising a resilient endless retainer removably engaging thefilter medium in the channel-shaped sides and conforming to the shape of the frame, and oppositely spaced relatively rigid elongated handle-forming'members secured to said band for removably interlocking same within the channel` shaped sides of the filter frame.

l2. A resilient means forretaining aflter medium in a desired position in a iilter frame, said means' comprising a pair of elongated springelements, a pair of elongated handle-forming clamping and stiiening elements, Veach of said spring elements having one encll thereof secured to one of said clamping and stitening elements and thel other References Cited in the ile of this patent A" l UNITED STATES PATENTS 1,385,502 Smith July 26, 1921 1,674,764 Dauphinec v June 26, 1928 1,691,967 lGammeter Nov. 20, 1928 Y 1,854,677 Umens'etter a Apr. 19. 1932 2,108,283 Drew et al. Feb. 15, 1938 2,449,102 Beager et al. Sept. 14, 1948 2,637,410

Y Manin May s, 1953 

